The purpose of Core B is three-fold: 1. To maintain and expand a complete and interactive database with accurate and robust demographic, phenotypic and clinical information that Is readily linked to the basic science information. 2. To provide investigators of Projects 1-5 with defined tissue samples (including DNA, serum, serology, cell lines, endoscopic biopsies, surgical resection tissues) as they are required and to ensure appropriate and evenhanded distribution to all projects. 3. To continue to 'call-back' patients with defined genetic, immunological or functional characteristics for re-sampling as required and requested by the projects. Core B obtains, processes and distributes tissues and also provides data management and both statistical advice and analyses in support of the projects. Blood, surgical and mucosal samples are processed for experimental use and/or storage, and comprehensive clinical, demographic and phenotypic data is gathered and entered into the secure database. All tissue samples are linked with the demographic, phenotypic and natural history data as well as with the associated immunologic and genetic parameters in an anonymized fashion. Following informed consent the procurement technician collects samples from clinical and research study patients at physician visits, endoscopic procedures and coordinates with surgeons and pathologists to obtain mucosal samples from intestinal resections. Populations are stratified according to a variety of clinical, subclinical, genetic and epidemiologic parameters. The services provided by Core B continue to expand with further intensification of clinical data collection and the recent expansion of genetic data. Database expansion to incorporate these and other data necessitate database management and statistical services to facilitate experiment design and data interpretation. The Research Studies Coordinators will help to identify and contact study populations and help with sample collection. Additional clinical services will be provided in cooperation with the Cedars-Sinai General Clinical Research Center.